Make New Entry, Make Followup Entry
User name miham
Log entry time 16:04:44 on May 11, 2009
Entry number 272610
This entry is a followup to: 272272
keyword=Problem with Dead TDC channels in BB dE-plane hopefully resolvedI went down into the Hall today in order to investigate the
problem with dead channels 9R and 16R in the dE plane.
I begun resolving problem the same way as I did
last time. I plugged the scope into the input to the
discriminators and check the signal. There was no signal
in both suspicious channels. I again (as in my first
attempt to fix the problem last week) start moving
the cables at the outputs from the (50/50) signal
splitter. Magically signals came back (Same as
last week). However, this time I decided to investigate
further and find the true problem. Bryan suggested me
to remove the splitter module and check if the resistors
are well attached to the connectors. When I did that I
realized that this was the true problem from the beginning.
In the attached pictures you can see, that the resistors in
these two channels were not soldered well enough. I have
also discovered some other channels that were about to
become bad. I have also realized that many of the
connectors on that module are loose, and should be reattached
otherwise we could loose other channels too. First I was trying
to reattach them and solder the bad channels back, but than I
decided to change the whole module with the new one. Hopefully
it will work now.
A copy of this log entry has been emailed to: sirca, moffit
Bad module
Bad Channel
Bad Channel
Bad Channel
